On Futurology

If history studies our past and social sciences study our present, what is the study of our future? Future(s) Studies (colloquially called "future(s)" by many of the field's practitioners) is an interdisciplinary field that seeks to hypothesize the possible, probable, preferable, or alternative future(s).

One of the fundamental assumptions in future(s) studies is that the future is plural rather than singular, that is, that it consists of alternative future(s) of varying degrees of likelihood but that it is impossible in principle to say with certainty which one will occur.

The homicide rate will continue to decline for years to come, but claiming it is entirely, or even mostly due to lead poisoning is amateurish, and there is little actual evidence (no, trend lines are NOT scientific evidence) that lead has directly caused any crime decline.

And at the same time, you can point to factors like amazing Emergency Room technology saving more lives. So, people may be getting shot or stabbed less often, but they are also surviving more of the shots/stabs they receive.

The problem with stuff like this is that "crime" or even "violent crime" is broad and multifactorial.

The only way to do a proper analysis is multivariate analysis which is complicated to get right if you don't have good statisticians on hand. The second problem is that the factors associated with crime span a wide variety of disciplines. ER techniques, improved response times, changes in demographics, causative risk factors 20 years removed from their effects, the economics of poverty, changes in policing strategy, and on and on.

So someone in one discipline will say something like "the recent relative economic prosperity is to be credited with the reduction in crime", while someone in another discipline will say "reduction in levels of lead led to increased IQ and reduced violent tendencies", but it's really very difficult to compare the relative magnitudes of these effects.

Optimally we'd be able to do a cost benefit analysis. At what point does the marginal cost of better enforcing of gun laws lead to a lower murder rate than the marginal cost of further reducing PPT of lead in the water / air?

Our (collective) grief at this argument is that there is an entire field of experts - all of whom are highly trained statisticians - who are devoted to the study of crime.

It's not as if the field of criminology is incapable of conducting rigorous multifarious analyses. We do that every day. We've done it looking at abortion and lead contamination, and don't find nearly as sizable or significant an effect as we do for new policing strategies, economic changes, and changing drug market dynamics.

Totally agree. I'm sure it has had some impact, but nothing near what has been reported by outlets like Mother Jones and the NY Times. Lead may explain a few percent of the variation in homicide, but perpetuating articles like this just amplifies the public belief that Freakonomics has it 100% right and the only place we need to look for the drop in crime is lead and Roe v Wade, and it is only a small fraction of what's being studied, and frankly the fraction with the least evidence.

One interesting question is if lower levels of lead that aren't actually medically classified as "chronic lead poisoning" might have more subtle behavioral effects on people. If so, then removing lead from gasoline and paint might have subtle effects on violence in larger parts of the population. That kind of question is very hard to study, unfortunately; there's too many variables.